urlcache.c

winNT技术操作系统,国外开放的原代码和LIUX一样

/***********************************************************************
 *           URLCache_DeleteEntry (Internal)
 *
 *  Deletes the specified entry and frees the space allocated to it
 *
 * RETURNS
 *    TRUE if it succeeded
 *    FALSE if it failed
 *
 */
static BOOL URLCache_DeleteEntry(LPURLCACHE_HEADER pHeader, CACHEFILE_ENTRY * pEntry)
{
    DWORD dwStartBlock;
    DWORD dwBlock;
    BYTE * AllocationTable = (LPBYTE)pHeader + ALLOCATION_TABLE_OFFSET;

    /* update allocation table */
    dwStartBlock = ((DWORD)((BYTE *)pEntry - (BYTE *)pHeader)) / BLOCKSIZE;
    for (dwBlock = dwStartBlock; dwBlock < dwStartBlock + pEntry->dwBlocksUsed; dwBlock++)
        URLCache_Allocation_BlockFree(AllocationTable, dwBlock);

    ZeroMemory(pEntry, pEntry->dwBlocksUsed * BLOCKSIZE);
    return TRUE;
}

/***********************************************************************
 *           URLCache_LocalFileNameToPathW (Internal)
 *
 *  Copies the full path to the specified buffer given the local file
 * name and the index of the directory it is in. Always sets value in
 * lpBufferSize to the required buffer size (in bytes).
 *
 * RETURNS
 *    TRUE if the buffer was big enough
 *    FALSE if the buffer was too small
 *
 */
static BOOL URLCache_LocalFileNameToPathW(
    const URLCACHECONTAINER * pContainer,
    LPCURLCACHE_HEADER pHeader,
    LPCSTR szLocalFileName,
    BYTE Directory,
    LPWSTR wszPath,
    LPLONG lpBufferSize)
{
    LONG nRequired;
    int path_len = strlenW(pContainer->path);
    int file_name_len = MultiByteToWideChar(CP_ACP, 0, szLocalFileName, -1, NULL, 0);
    if (Directory >= pHeader->DirectoryCount)
    {
        *lpBufferSize = 0;
        return FALSE;
    }

    nRequired = (path_len + DIR_LENGTH + file_name_len + 1) * sizeof(WCHAR);
    if (nRequired < *lpBufferSize)
    {
        int dir_len;

        memcpy(wszPath, pContainer->path, path_len * sizeof(WCHAR));
        dir_len = MultiByteToWideChar(CP_ACP, 0, pHeader->directory_data[Directory].filename, DIR_LENGTH, wszPath + path_len, DIR_LENGTH);
        wszPath[dir_len + path_len] = '\\';
        MultiByteToWideChar(CP_ACP, 0, szLocalFileName, -1, wszPath + dir_len + path_len + 1, file_name_len);
        *lpBufferSize = nRequired;
        return TRUE;
    }
    *lpBufferSize = nRequired;
    return FALSE;
}

/***********************************************************************
 *           URLCache_LocalFileNameToPathA (Internal)
 *
 *  Copies the full path to the specified buffer given the local file
 * name and the index of the directory it is in. Always sets value in
 * lpBufferSize to the required buffer size.
 *
 * RETURNS
 *    TRUE if the buffer was big enough
 *    FALSE if the buffer was too small
 *
 */
static BOOL URLCache_LocalFileNameToPathA(
    const URLCACHECONTAINER * pContainer,
    LPCURLCACHE_HEADER pHeader,
    LPCSTR szLocalFileName,
    BYTE Directory,
    LPSTR szPath,
    LPLONG lpBufferSize)
{
    LONG nRequired;
    int path_len, file_name_len, dir_len;

    if (Directory >= pHeader->DirectoryCount)
    {
        *lpBufferSize = 0;
        return FALSE;
    }

    path_len = WideCharToMultiByte(CP_ACP, 0, pContainer->path, -1, NULL, 0, NULL, NULL);
    file_name_len = strlen(szLocalFileName);
    dir_len = DIR_LENGTH;

    nRequired = (path_len + dir_len + 1 + file_name_len) * sizeof(WCHAR);
    if (nRequired < *lpBufferSize)
    {
        WideCharToMultiByte(CP_ACP, 0, pContainer->path, -1, szPath, -1, NULL, NULL);
        memcpy(szPath+path_len, pHeader->directory_data[Directory].filename, dir_len);
        szPath[path_len + dir_len] = '\\';
        memcpy(szPath + path_len + dir_len + 1, szLocalFileName, file_name_len);
        *lpBufferSize = nRequired;
        return TRUE;
    }
    *lpBufferSize = nRequired;
    return FALSE;
}

/***********************************************************************
 *           URLCache_CopyEntry (Internal)
 *
 *  Copies an entry from the cache index file to the Win32 structure
 *
 * RETURNS
 *    TRUE if the buffer was big enough
 *    FALSE if the buffer was too small
 *
 */
static BOOL URLCache_CopyEntry(
    URLCACHECONTAINER * pContainer,
    LPCURLCACHE_HEADER pHeader, 
    LPINTERNET_CACHE_ENTRY_INFOA lpCacheEntryInfo, 
    LPDWORD lpdwBufferSize, 
    URL_CACHEFILE_ENTRY * pUrlEntry,
    BOOL bUnicode)
{
    int lenUrl;
    DWORD dwRequiredSize = sizeof(*lpCacheEntryInfo);

    if (*lpdwBufferSize >= dwRequiredSize)
    {
        lpCacheEntryInfo->lpHeaderInfo = NULL;
        lpCacheEntryInfo->lpszFileExtension = NULL;
        lpCacheEntryInfo->lpszLocalFileName = NULL;
        lpCacheEntryInfo->lpszSourceUrlName = NULL;
        lpCacheEntryInfo->CacheEntryType = pUrlEntry->CacheEntryType;
        lpCacheEntryInfo->u.dwExemptDelta = pUrlEntry->dwExemptDelta;
        lpCacheEntryInfo->dwHeaderInfoSize = pUrlEntry->dwHeaderInfoSize;
        lpCacheEntryInfo->dwHitRate = pUrlEntry->dwHitRate;
        lpCacheEntryInfo->dwSizeHigh = pUrlEntry->dwSizeHigh;
        lpCacheEntryInfo->dwSizeLow = pUrlEntry->dwSizeLow;
        lpCacheEntryInfo->dwStructSize = sizeof(*lpCacheEntryInfo);
        lpCacheEntryInfo->dwUseCount = pUrlEntry->dwUseCount;
        DosDateTimeToFileTime(pUrlEntry->wExpiredDate, pUrlEntry->wExpiredTime, &lpCacheEntryInfo->ExpireTime);
        lpCacheEntryInfo->LastAccessTime.dwHighDateTime = pUrlEntry->LastAccessTime.dwHighDateTime;
        lpCacheEntryInfo->LastAccessTime.dwLowDateTime = pUrlEntry->LastAccessTime.dwLowDateTime;
        lpCacheEntryInfo->LastModifiedTime.dwHighDateTime = pUrlEntry->LastModifiedTime.dwHighDateTime;
        lpCacheEntryInfo->LastModifiedTime.dwLowDateTime = pUrlEntry->LastModifiedTime.dwLowDateTime;
        DosDateTimeToFileTime(pUrlEntry->wLastSyncDate, pUrlEntry->wLastSyncTime, &lpCacheEntryInfo->LastSyncTime);
    }

    if ((dwRequiredSize % 4) && (dwRequiredSize < *lpdwBufferSize))
        ZeroMemory((LPBYTE)lpCacheEntryInfo + dwRequiredSize, 4 - (dwRequiredSize % 4));
    dwRequiredSize = DWORD_ALIGN(dwRequiredSize);
    if (bUnicode)
        lenUrl = MultiByteToWideChar(CP_ACP, 0, pUrlEntry->szSourceUrlName, -1, NULL, 0);
    else
        lenUrl = strlen(pUrlEntry->szSourceUrlName);
    dwRequiredSize += lenUrl + 1;
    
    /* FIXME: is source url optional? */
    if (*lpdwBufferSize >= dwRequiredSize)
    {
        lpCacheEntryInfo->lpszSourceUrlName = (LPSTR)lpCacheEntryInfo + dwRequiredSize - lenUrl - 1;
        if (bUnicode)
            MultiByteToWideChar(CP_ACP, 0, pUrlEntry->szSourceUrlName, -1, (LPWSTR)lpCacheEntryInfo->lpszSourceUrlName, lenUrl + 1);
        else
            memcpy(lpCacheEntryInfo->lpszSourceUrlName, pUrlEntry->szSourceUrlName, (lenUrl + 1) * sizeof(CHAR));
    }

    if ((dwRequiredSize % 4) && (dwRequiredSize < *lpdwBufferSize))
        ZeroMemory((LPBYTE)lpCacheEntryInfo + dwRequiredSize, 4 - (dwRequiredSize % 4));
    dwRequiredSize = DWORD_ALIGN(dwRequiredSize);

    if (pUrlEntry->dwOffsetLocalName)
    {
        LONG nLocalFilePathSize;
        LPSTR lpszLocalFileName;
        lpszLocalFileName = (LPSTR)lpCacheEntryInfo + dwRequiredSize;
        nLocalFilePathSize = *lpdwBufferSize - dwRequiredSize;
        if ((bUnicode && URLCache_LocalFileNameToPathW(pContainer, pHeader, (LPCSTR)pUrlEntry + pUrlEntry->dwOffsetLocalName, pUrlEntry->CacheDir, (LPWSTR)lpszLocalFileName, &nLocalFilePathSize)) ||
            URLCache_LocalFileNameToPathA(pContainer, pHeader, (LPCSTR)pUrlEntry + pUrlEntry->dwOffsetLocalName, pUrlEntry->CacheDir, lpszLocalFileName, &nLocalFilePathSize))
        {
            lpCacheEntryInfo->lpszLocalFileName = lpszLocalFileName;
        }
        dwRequiredSize += nLocalFilePathSize;

        if ((dwRequiredSize % 4) && (dwRequiredSize < *lpdwBufferSize))
            ZeroMemory((LPBYTE)lpCacheEntryInfo + dwRequiredSize, 4 - (dwRequiredSize % 4));
        dwRequiredSize = DWORD_ALIGN(dwRequiredSize);
    }
    dwRequiredSize += pUrlEntry->dwHeaderInfoSize + 1;

    if (*lpdwBufferSize >= dwRequiredSize)
    {
        lpCacheEntryInfo->lpHeaderInfo = (LPBYTE)lpCacheEntryInfo + dwRequiredSize - pUrlEntry->dwHeaderInfoSize - 1;
        memcpy(lpCacheEntryInfo->lpHeaderInfo, (LPSTR)pUrlEntry + pUrlEntry->dwOffsetHeaderInfo, pUrlEntry->dwHeaderInfoSize);
        ((LPBYTE)lpCacheEntryInfo)[dwRequiredSize - 1] = '\0';
    }
    if ((dwRequiredSize % 4) && (dwRequiredSize < *lpdwBufferSize))
        ZeroMemory((LPBYTE)lpCacheEntryInfo + dwRequiredSize, 4 - (dwRequiredSize % 4));
    dwRequiredSize = DWORD_ALIGN(dwRequiredSize);

    if (dwRequiredSize > *lpdwBufferSize)
    {
        *lpdwBufferSize = dwRequiredSize;
        SetLastError(ERROR_INSUFFICIENT_BUFFER);
        return FALSE;
    }
    *lpdwBufferSize = dwRequiredSize;
    return TRUE;
}


/***********************************************************************
 *           URLCache_SetEntryInfo (Internal)
 *
 *  Helper for SetUrlCacheEntryInfo{A,W}. Sets fields in URL entry
 * according the the flags set by dwFieldControl.
 *
 * RETURNS
 *    TRUE if the buffer was big enough
 *    FALSE if the buffer was too small
 *
 */
static BOOL URLCache_SetEntryInfo(URL_CACHEFILE_ENTRY * pUrlEntry, const INTERNET_CACHE_ENTRY_INFOW * lpCacheEntryInfo, DWORD dwFieldControl)
{
    if (dwFieldControl & CACHE_ENTRY_ACCTIME_FC)
        pUrlEntry->LastAccessTime = lpCacheEntryInfo->LastAccessTime;
    if (dwFieldControl & CACHE_ENTRY_ATTRIBUTE_FC)
        pUrlEntry->CacheEntryType = lpCacheEntryInfo->CacheEntryType;
    if (dwFieldControl & CACHE_ENTRY_EXEMPT_DELTA_FC)
        pUrlEntry->dwExemptDelta = lpCacheEntryInfo->u.dwExemptDelta;
    if (dwFieldControl & CACHE_ENTRY_EXPTIME_FC)
        FIXME("CACHE_ENTRY_EXPTIME_FC unimplemented\n");
    if (dwFieldControl & CACHE_ENTRY_HEADERINFO_FC)
        FIXME("CACHE_ENTRY_HEADERINFO_FC unimplemented\n");
    if (dwFieldControl & CACHE_ENTRY_HITRATE_FC)
        pUrlEntry->dwHitRate = lpCacheEntryInfo->dwHitRate;
    if (dwFieldControl & CACHE_ENTRY_MODTIME_FC)
        pUrlEntry->LastModifiedTime = lpCacheEntryInfo->LastModifiedTime;
    if (dwFieldControl & CACHE_ENTRY_SYNCTIME_FC)
        FileTimeToDosDateTime(&lpCacheEntryInfo->LastAccessTime, &pUrlEntry->wLastSyncDate, &pUrlEntry->wLastSyncTime);

    return TRUE;
}

/***********************************************************************
 *           URLCache_HashKey (Internal)
 *
 *  Returns the hash key for a given string
 *
 * RETURNS
 *    hash key for the string
 *
 */
static DWORD URLCache_HashKey(LPCSTR lpszKey)
{
    /* NOTE: this uses the same lookup table as SHLWAPI.UrlHash{A,W}
     * but the algorithm and result are not the same!
     */
    static const unsigned char lookupTable[256] = 
    {
        0x01, 0x0E, 0x6E, 0x19, 0x61, 0xAE, 0x84, 0x77,
        0x8A, 0xAA, 0x7D, 0x76, 0x1B, 0xE9, 0x8C, 0x33,
        0x57, 0xC5, 0xB1, 0x6B, 0xEA, 0xA9, 0x38, 0x44,
        0x1E, 0x07, 0xAD, 0x49, 0xBC, 0x28, 0x24, 0x41,
        0x31, 0xD5, 0x68, 0xBE, 0x39, 0xD3, 0x94, 0xDF,
        0x30, 0x73, 0x0F, 0x02, 0x43, 0xBA, 0xD2, 0x1C,
        0x0C, 0xB5, 0x67, 0x46, 0x16, 0x3A, 0x4B, 0x4E,
        0xB7, 0xA7, 0xEE, 0x9D, 0x7C, 0x93, 0xAC, 0x90,
        0xB0, 0xA1, 0x8D, 0x56, 0x3C, 0x42, 0x80, 0x53,
        0x9C, 0xF1, 0x4F, 0x2E, 0xA8, 0xC6, 0x29, 0xFE,
        0xB2, 0x55, 0xFD, 0xED, 0xFA, 0x9A, 0x85, 0x58,
        0x23, 0xCE, 0x5F, 0x74, 0xFC, 0xC0, 0x36, 0xDD,
        0x66, 0xDA, 0xFF, 0xF0, 0x52, 0x6A, 0x9E, 0xC9,
        0x3D, 0x03, 0x59, 0x09, 0x2A, 0x9B, 0x9F, 0x5D,
        0xA6, 0x50, 0x32, 0x22, 0xAF, 0xC3, 0x64, 0x63,
        0x1A, 0x96, 0x10, 0x91, 0x04, 0x21, 0x08, 0xBD,
        0x79, 0x40, 0x4D, 0x48, 0xD0, 0xF5, 0x82, 0x7A,
        0x8F, 0x37, 0x69, 0x86, 0x1D, 0xA4, 0xB9, 0xC2,
        0xC1, 0xEF, 0x65, 0xF2, 0x05, 0xAB, 0x7E, 0x0B,
        0x4A, 0x3B, 0x89, 0xE4, 0x6C, 0xBF, 0xE8, 0x8B,
        0x06, 0x18, 0x51, 0x14, 0x7F, 0x11, 0x5B, 0x5C,
        0xFB, 0x97, 0xE1, 0xCF, 0x15, 0x62, 0x71, 0x70,
        0x54, 0xE2, 0x12, 0xD6, 0xC7, 0xBB, 0x0D, 0x20,
        0x5E, 0xDC, 0xE0, 0xD4, 0xF7, 0xCC, 0xC4, 0x2B,
        0xF9, 0xEC, 0x2D, 0xF4, 0x6F, 0xB6, 0x99, 0x88,
        0x81, 0x5A, 0xD9, 0xCA, 0x13, 0xA5, 0xE7, 0x47,
        0xE6, 0x8E, 0x60, 0xE3, 0x3E, 0xB3, 0xF6, 0x72,
        0xA2, 0x35, 0xA0, 0xD7, 0xCD, 0xB4, 0x2F, 0x6D,
        0x2C, 0x26, 0x1F, 0x95, 0x87, 0x00, 0xD8, 0x34,
        0x3F, 0x17, 0x25, 0x45, 0x27, 0x75, 0x92, 0xB8,
        0xA3, 0xC8, 0xDE, 0xEB, 0xF8, 0xF3, 0xDB, 0x0A,
        0x98, 0x83, 0x7B, 0xE5, 0xCB, 0x4C, 0x78, 0xD1
    };
    BYTE key[4];
    DWORD i;
    int subscript[sizeof(key) / sizeof(key[0])];

    subscript[0] = *lpszKey;
    subscript[1] = (char)(*lpszKey + 1);
    subscript[2] = (char)(*lpszKey + 2);
    subscript[3] = (char)(*lpszKey + 3);

    for (i = 0; i < sizeof(key) / sizeof(key[0]); i++)
        key[i] = lookupTable[i];

    for (lpszKey++; *lpszKey && ((lpszKey[0] != '/') || (lpszKey[1] != 0)); lpszKey++)
    {
        for (i = 0; i < sizeof(key) / sizeof(key[0]); i++)
            key[i] = lookupTable[*lpszKey ^ key[i]];
    }

    return *(DWORD *)key;
}

static inline HASH_CACHEFILE_ENTRY * URLCache_HashEntryFromOffset(LPCURLCACHE_HEADER pHeader, DWORD dwOffset)
{
    return (HASH_CACHEFILE_ENTRY *)((LPBYTE)pHeader + dwOffset);
}

static BOOL URLCache_FindHash(LPCURLCACHE_HEADER pHeader, LPCSTR lpszUrl, struct _HASH_ENTRY ** ppHashEntry)
{
    /* structure of hash table:
     *  448 entries divided into 64 blocks
     *  each block therefore contains a chain of 7 key/offset pairs
     * how position in table is calculated:
     *  1. the url is hashed in helper function
     *  2. the key % 64 * 8 is the offset
     *  3. the key in the hash table is the hash key aligned to 64
     *
     * note:
     *  there can be multiple hash tables in the file and the offset to
     *  the next one is stored in the header of the hash table
     */
    DWORD key = URLCache_HashKey(lpszUrl);
    DWORD offset = (key % HASHTABLE_NUM_ENTRIES) * sizeof(struct _HASH_ENTRY);
    HASH_CACHEFILE_ENTRY * pHashEntry;
    DWORD dwHashTableNumber = 0;

    key = (DWORD)(key / HASHTABLE_NUM_ENTRIES) * HASHTABLE_NUM_ENTRIES;

    for (pHashEntry = URLCache_HashEntryFromOffset(pHeader, pHeader->dwOffsetFirstHashTable);
         ((DWORD)((LPBYTE)pHashEntry - (LPBYTE)pHeader) >= ENTRY_START_OFFSET) && ((DWORD)((LPBYTE)pHashEntry - (LPBYTE)pHeader) < pHeader->dwFileSize);
         pHashEntry = URLCache_HashEntryFromOffset(pHeader, pHashEntry->dwAddressNext))
    {
        int i;
        if (pHashEntry->dwHashTableNumber != dwHashTableNumber++)
        {
            ERR("Error: not right hash table number (%ld) expected %ld\n", pHashEntry->dwHashTableNumber, dwHashTableNumber);
            continue;
        }
        /* make sure that it is in fact a hash entry */
        if (pHashEntry->CacheFileEntry.dwSignature != HASH_SIGNATURE)
        {
            ERR("Error: not right signature (\"%.4s\") - expected \"HASH\"\n", (LPCSTR)&pHashEntry->CacheFileEntry.dwSignature);
            continue;
        }

        for (i = 0; i < HASHTABLE_BLOCKSIZE; i++)
        {
            struct _HASH_ENTRY * pHashElement = &pHashEntry->HashTable[offset + i];
            if (key == (DWORD)(pHashElement->dwHashKey / HASHTABLE_NUM_ENTRIES) * HASHTABLE_NUM_ENTRIES)
            {
                /* FIXME: we should make sure that this is the right element
                 * before returning and claiming that it is. We can do this
                 * by doing a simple compare between the URL we were given
                 * and the URL stored in the entry. However, this assumes
                 * we know the format of all the entries stored in the
                 * hash table */
                *ppHashEntry = pHashElement;
                return TRUE;
            }
        }
    }
    return FALSE;
}